Why do I get this error when trying to install?

and kept getting this error Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, webmaster@thebig305.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

Where have you uploaded the freichat folder .
Make sure you point the browser to the correct path to the folder .

Also try playing with the permissions of the folder .

I have uploaded the folder in to my tmp folder and unzip it there to install from front end of joomla and tried to install from extension manager. No luck

please help me with this... I have literally followed all instructions but keep coming up with this error "JInstaller: :Install: Cannot find XML setup file
Path does not have a valid package."

Let me make it clear , FreiChatX is not a Joomla module to be installed directly .

Please watch this video
http://evnix.com/drupal2/node/424